Highway crossing signaling system



Jan 7, 1936. v D, J, MCCARTHY 2,027,188

HIGHWAY CROSSING SIGNALING SYSTEM Filed May 23, 1934 J wloi Fa) m Pig/gF i a 3% (a \J" J W K INVENTOR DANIEL J. McCARTHY (34% MATH i atenteclJan. 7, 1933 7 U ET E ,MPEATENT OFFICE 2,627,188 HIGHWAY CROSSINGSEGNALING SYSTEM DanielJ,.McCarthmElgin,IlL, assignor to Asso-' elatedElectric Laboratories, Inc., Chicago, 111., a co'rporationof Delaware'Application-May-23', 1934;, Serial lvohizmozc 6 Claims. (01.246-1-126')"The present invention relates in general to railway crossing signalcontrol-circuits for" controlling signals or otherapparatuslocated atintersectionsof railways and highways to warn those using the highwayswhen a train is ap- --proaching. I

In the present highway crossing signal systems there is--no"provisionfor differentiating between high and low speed trains approachingacross- 0' --ing, and-the-crossing signal is operated-from a definiteand" fixeddistance from the crossing by all trains regardless of theirapproaching speedn The operating elementgoperated by thea-pproachingtrain for controlling" the crossing signal; must be putthemaximum distance away fronr the-crossing to give adequate-warningagainstthe fastest trains. Under "this condition, a train-approaching ataslowrate of speed will -operate the crossing signal and stop highway ggtrafficdonger than is necessary. This long signaling :operationbeforethe slowlyapproaching train actually reaches the crossinghasproven -'-dangerous because it invites careless motorists totakechances-in passing over the'crossing while the train is approachingandthe signal is operating.

Accordingly, the mainobject of the present invention is the provision ofnew and novel circuit arrangements for differentiatingbetween high --andslow speed trains "approaching a crosslng' so that the timelengthofthewarning'given by the signal before the trainactually reaches the cross-'ing is substantially the sameior fast andslow moving trains.

The above and other objects will be apparent 'from'thefollowingspecification when read in connection with the accompanyingdrawing.

Referring nowto the drawing, T represents the ""two rails'of a railroadtrack-on which trains l opproach the highway=crossing in the directionindicated by thearrows Alongthe-inside of one of the. rails areplacedcontactors 2, 3, 4, 5; and 6 which are operated. by the wheels ofa train when Hpassing thereover; These contactors may be substantiallyof the same design and operation as disclosed in theapplication oi..H.F. Obergfell and'G. W. Eickenberg, Serial No. 639,558,.filed ,"October26, 1932, wherein the. plunger is operated by the train wheels to cause.the" operation of the circuit controlling contacts inmtheassociatedhousing. The corresponding circuit controlling 1, scontactsin'thepresent. drawing are indicated at '5 2,3, 4, 5, and 6whereinsuchcontacts are operatedby the associated: plungers representedby small circles placed along the inside of the lower rail.

The contactor 2 is placed on the. left-handside of the highway crossing,the contactor 3 on,the

right-hand side of the highway crossing,;-and the contactors 4, 5, and6.. at varying distancesfrom the crossing best suited to accomplish thedesired -result as more fully explained hereinafter.

A highway crossing signaldesignated as ,l ,:may

-be of the fiashing,.audible, or any standard crossingsignal typeincluding automatic gates, The contacts of the. contactor controlcircuits of a number of relays, :two of which--namely, relays 8 and9-are of the slow-releasing type,,,having copper slugs on their armatureends as, indicated by the cross-hatched sections .thereoi. ll, l3, and26 designate batteries forcontrolling the operation of the highwaysignal I andgthe relays. If desired, 26 and I3 may be considered as thesame battery. The relays, contactors,;and circuits are shown in theirnormal .condition or at a time when there is no signal being given atthe highway crossing. Since all of the relays, except relay ID, arenormally energized, it is believed advisable to describe the circuitsbymeans of which such relays are maintained in their normal operatedpositions.

The circuit for maintaining relay l2 energized extends from one pole ofbattery .l3, ,through armature ll, winding of relay l2, armatureof relayl6, and conductors I5 and M to theother pole of battery I3. Relay I6 ismaintained energized over a circuit extending from one pole'of batteryl3, armature l1, winding of relay l6, and conductor M to the other poleor battery l3.

Relay I8 is maintained energized over the-following stick circuit: Fromone pole of battery '13, through the winding of relay l8, armatur'e123,contacts of contactor 3, conductor 2|,1 lower normally closed contactsof contactor 4, conductor 20, contacts of contactor 5, and conductorsllfl and 14 to the other pole of battery l3. Thecircuit 'for maintainingrelay 9 energized extends ,from

one pole of battery 26, through the winding of relay 9, and armature 31to the other poleof battery 26. Relay 8 is maintained energized over asimilar circuit including armature30. Relay I is maintained energizedover a locking or socalled stick circuit as follows: From one pole ofbattery 26, armature 28, winding of relay Land contacts controlled bycontactor B to the other pole of battery 26.

r In order to describe the invention it will be assumed that a train isapproaching the high- Way crossing in the direction indicatedby thearrow and that in so doing the wheels of the train operate contactor 6to open the associated contacts. In response to the opening of thecontacts controlled by contactor B the stick circuit of relay 1 isopened with the result that this relay thereupon deenergizes. Atarmature 28 relay I removes a shunt from around contacts 34 of contactor4 and at armature 38 opens the circuit to slow releasing relay 3. Afteran interval slow releasing relay 8 deenergizes and at armature 3i opensthe circuit of slow releasing relay 9. If desired, additional slowreleasing relays, such as 8 and 3, may be added and connected in a likemanner to increase the time interval before the last of such relaysdeenergize. After an interval the last slow releasing relay, in thiscase relay 3, deenergizes and at armature 32 completes the circuit forenergizing relay III over the following circuit: From one pole ofbattery 26, winding of relay I3, and armature 32 now closed to the otherpole of battery. At armature 33 relay Iii closes a shunt around thecontacts controlled by contactor 5.

The operation from this point on is different dependent upon the speedof the approaching train or is dependent upon whether the contactscontrolled by contactor 5 have been operated by the train before relayI3 has been energized to close contacts 33. In case of a fast train thecontactor 5 will be operated before relay III has had time to energizeand close contacts 33 while in the case of a slow train the relay I3 hashad sufficient time to energize and close its contacts 33 to shunt thecontacts controlled by contactor 5.

It will now be assumed that the train approaching is a fast train andtherefore the contacts controlled by contactor 5 are operated beforerelay It] operates its armature contacts 33. Under this condition theoperation of the contacts controlled by contactor 5 opens the previouslytraced stick circuit for relay I 8 whereupon relay I8 deenergizes. Atarmature 23 relay It opens a further point in its stick circuit and atarmature I? opens the previously traced circuits of relays I2 and I3whereupon such relays deenergize. At the contacts controlled by relay ita further point is opened in the circuit of relayIZ, At armature 23relay I2 closes the circuit for operating the highway crossing signal Iover an obvious circuit. From the foregoing it will be seen that a fasttrain starts the operation of highway signal I in response to theoperation of contactor 5.

In the case of a slowly approaching train the signal I will not startoperating until the train reaches and operates the contacts controlledby contactor 4. In response to'a slowly approaching train operatingcontactor I5, relays I, 8, and 9 deenergize and relay I0 energizes aspreviously described. In this case relay It has energized and closedcontacts 33 before the slowly approaching train has operated contactor 5and therefore, since contacts 33 shunt the contacts controlled bycontactor 5, the operation of these contactor contacts is Withouteffect. During the time the contacts controlled by contactor 3 are openthe stick circuit for relay I3 is maintained through contacts 33 ofrelay I 0. When the slow train operates contactor I the stick circuit ofrelay I3 is opened at the lower normally closed contacts with the'resultthat relays I3, I6, and I2 deenergize and highway signal I is operatedas previously described. From the foregoing it will be seen that a fasttrain operates the highway signal when contactor 3 is operated and aslow train operates the highway signal when the contactor 4 is operated.Contactors 4 and 5 are therefore placed at suflicient distances from thecrossing so that signal I will operate for substantially the same lengthof time before the train, whether fast or slow, actually reaches thecrossing.

Each train, regardless of whether it is a fast train or a slow train,prepares the circuits so as to be reset for the next train. Whenever atrain operates contactor 4, contacts 36 close an energizing circuit forrelay I as follows: From one pole of battery 26, conductor 33, contacts3 conductor 31, winding of relay I, and contacts controlled by contactor6 to the other pole of battery 26. At armature 28 relay '1 closes itsstick circuit and at armature 33 completes the circuit for energizingslow-to-release relay 3. At armature 3|, relay 8, upon energizing,closes the energizing circuit of relay 9. Relay 3, upon energizing, at20 armature 32 opens the circuit of relay II) which thereupondeenergizes to open at armature 33 the shunt circuit around the contactsof con tactor 5. Relays I, 8, 3, and III are now reset in their normalcondition in preparation for the next approaching train.

Contactors 2 and 3 are positioned with respect to each other so thatthey would be spanned by one or two cars of a train in such a way thatwhen contactor 2 is closed contactor 3 would be immediately opened ifthe train still spans the crossing. This arrangement prevents thereenergization of relay I8 until the last car has cleared the crossingso that signal I will continue to operate as long as any portion of thetrain is on 35 the crossing. However, when the last car passes thecrossing contactor 2 is operated to close its contacts at a time whenthe contacts controlled by contactor 3 are closed. Under this conditiona circuit may be traced for energizing relay I8 as follows: From onepole of battery I3, winding of relay I 8, contacts of contactor 2 nowclosed, contacts of contactor 3 now closed, conductor 2|, lower normallyclosed contacts of contactor 4, conductor 23, normally closed contactsof contactor 5, and conductors I9 and I I to the other pole of batteryI3. At armature 23 relay I8 closes its previously traced stick circuitthrough contactors 3, 4, and 5 and at armature I'I completes the circuitfor energizing slow-to-operate relay I3. Relay I6, upon energizing,completes at its armature a circuit for energizing slow-to-release relayI2 by way of armature I'i. Relay I2, upon energizing, at armature 25opens the circuit to highway signal I, whereupon the signal ceases tooperate. Slow-to-operate relays have copper slugs on their heel end asindicated by the upper full black section of relay I5. All of theapparatus is back to normal condition ready to operate in the samemanner as just described for the next approaching train.

In a co-pending application executed by me of even date herewith, SerialNo. 727,025, filed May 23, 1934, I have shown and described circuitarrangements whereby the speed of a train between two given pointsdetermines whether or not a signal is to be operated. From the foregoingdescription it will be seen that this feature is also disclosed in thepresent application wherein the speed of the train between contactors 6and 5 determines whether signal I is to be operated in response to theoperation of contactor 5 or in response to the operation of contactor 4.In the co-pending application a railroad grade crossing signal isoperated to danger position or remains in -.e-,ozr ,res J the clear;'position 'togovern "whether the train 1 mfay proceed across therailroad'grade crossing dependent upon the speed of 1 the *trainbetweentwo 'givenpoints; while'intthe instant application the highway crossingsignal is operatedor not operated in response to the Operation ofconbetween contactors 6 and 5. The co-pending apto the specificdisclosures not. shown :in the copending application.

Itwill be .understoodthat while only one track with traffic inone'direction has been illustrated,

a similar arrangement is provided for a second track having traflic inthe opposite direction. Also while the circuits and arrangements providefor trains having speeds within two limits, it will be understood thatany number of limits can be had by multiplying the units in an obviousmannner.

What is considered new and is desired to have protected by LettersPatent is set forth in the appended claims.

What is claimed is:

1. In a signaling system for signaling the approach of trains at acrossing, a plurality of contacts located at predetermined points alongthe track and operable in succession by a train approaching thecrossing, a normally energized start relay, a stick circuit for saidstart relay in-' cluding the first of said contacts to be encountered bythe train, said stick circuit opened in response to the train operatingthe said first con tact to release said start relay, a normallyenergized signal controlling relay, a stick circuit for said relayincluding the second and third of said contacts successively operated byan approaching train, slow releasing means initiated in response to therelease of said start relay, means operated by said slow-releasing meansfor shunting the said second contacts after a predetermined time tomaintain the stick circuit of said signal controlling relay only in casethe said second contacts are operated after said second train operatedcontacts are shunted, and the operation of said third contacts by theapproaching train thereafter opening said stick circuit to release saidsignal controlling relay.

2. In a signaling system for signaling the approach of trains at acrossing, a plurality of contacts located at predetermined points alongthe track and operable in succession by a train ap-' proaching thecrossing, a normally energized start relay, a stick circuit for saidstart relay including the first of said contacts to be encountered bythe train, said stick circuit opened in response to the train operatingthe said first contact to release said start relay, a normally energizedsignal controlling relay, a stick circuit for said relay including thesecond and third of said contacts successively operated by anapproaching train, slow-releasing means initiated in response to therelease of said start relay, means operated by said slow releasing meansfor shunting the said second contacts after a predetermined time tomaintain the stick circuit of said signal controlling relay only in casethe said second contacts are operated after said second train operatedcontacts are shunted, the operation of said third contacts by theapproaching train thereafter opening said stick circuit to release saidstart and relay, and means controlled by some of said contacts whenoperated for retactor dependent upon the' speedof-the train "-ingtrain,said stick circuit opened in response to the-train operating said firstcontact to release saidrelay, slow releasing means initiated in--resaidslow-releasing means.

' 3: -In asignaling system for signaling the approach oftrains at acrossing, a plurality of contacts-located at predetermined points alongthe 5 track and-operable in succession by a train approachingthecrossing, a normally energized start relay, a stick circuit for saidrelay including the first of said contacts operated by an approachsponseto the release of said start relay, anormally openzshunt circuitaround'the second of said contactsymeans operated by i said slow-actingmeans for closing said shunt circuit around the said second contactsafter a predetermined time, a signal controlling relay operated inresponse to the operation of either said second or third contactsdependent upon whether said shunt circuit is openedor closed at the timethe said second contacts are operated by the approaching train, andsignaling means at said crossing operated in response to the operationof said signal relay to warn traffic of an approaching train.

4. In a signaling system for signaling the approach of trains at acrossing, a plurality of contacts located at predetermined points alongthe track and operable in succession by a train approaching thecrossing, a normally energized start relay, a stick circuit for saidstart relay, said stick circuit opened in response to an approachingtrain operating the first encountered one of said contacts to releasesaid start relay, a chain of normally energized slow-releasing relaysinitiated in their releasing operations in response to the operation ofsaid start relay, a normally open shunt circuit around the. second ofsaid contacts, means responsive to the release of the last slowreleasing relay in the chain for 40 closing said shunt circuit aroundthe said second contacts, a signal controlling relay, said signal relayoperated in response to the operation of either said second or saidthird contacts dependent upon whether said shunt circuit is open orclosed at the time said second contacts are first operated by theapproaching train.

5. In a signaling system for signaling the approach of trains at acrossing, a plurality of contacts located at predetermined points alongthe track and operable in succession by a train approaching thecrossing, a normally energized start relay, a stick circuit for saidstart relay, said stick circuit opened in response to an approachingtrain operating the first encountered one of said contacts to releasesaid start relay,

a chain of normally energized slow-releasing relays initiated in theirreleasing operations in response to the operation of said start relay, anormally open shunt circuit around the second of said contacts, meansresponsive to the release of the last slow-releasing relay in the chainfor closing said shunt circuit around thesaid second contacts, a signalcontrolling relay, said signal relay operated in reponse to theoperation of either said second or said third contacts dependent uponwhether said shunt circuit is open or closed at the time said secondcontacts are first operated by the approaching train, and other of saidcontacts operated by said train for reenergizing said start relay tocomplete its stick circuit and reset said chain of relays and forresetting said signal relay. 6. In a highway crossing signaling system,a

. highway signal and control means therefor having a slow operatingdevice initially started in operation in response to the operation ofsaid first set of contacts by a train approaching the crossing, anormally open shunt circuit around said second set of contacts, meansoperated by said slow operating device when fully operated for closingsaid shunt circuit around said second set of contacts, said signalcontrol means and said signal always operated in response to the openingof said series circuit by the train operating said third set ofcontacts, said signal control means and signal operated in response tothe operation of said second set of contacts by the train opening saidseries circuit only in case said second set of contacts are operatedbefore said slow operating device is fully operated to close said shuntcircuit around said second set of contacts, and the operation of saidfourth set of contacts by said train maintaining said series circuitopen to maintain said signal control means and signal in operatedcondition.

DANIEL J. MCCARTHY.

